Physics of Energy-Momentum Tensor Form Factors: Mass, Spin, and Forces

In recent years, the form factors of the energy-momentum tensor of hadrons have attracted considerable attention in experiments, lattice calculations and modelings. In this talk, I will review some of physics motivations including mass and spin structure, momentum flow and forces. I will focus on the role of the QCD trace anomaly which might be the key to understand the origin of mass as well as the quark confining forces.